Exposure to ozone causes a decrease in spirometric lung function and an increase in airway inflammation in healthy young adults at concentrations as low as 0.08 ppm, close to the National Ambient Air Quality Standard for ground level ozone.
To test whether airway effects occur below the current ozone standard and if they are more pronounced in potentially susceptible individuals, such as those deficient in the antioxidant gene glutathione S-transferase mu 1 (GSTM1).
Pulmonary function and subjective symptoms were measured in 59 healthy young adults (19-35 yr) immediately before and after exposure to 0.0 (clean air, CA) and 0.06 ppm ozone for 6.6 hours in a chamber while undergoing intermittent moderate exercise. The polymorphonuclear neutrophil (PMN) influx was measured in 24 subjects 16 to 18 hours postexposure.
Subjects experienced a significantly greater (P = 0.008) change in FEV(1) (± SE) immediately after exposure to 0.06 ppm ozone compared with CA (-1.71 ± 0.50% vs. -0.002 ± 0.46%). The decrement in FVC was also greater (P = 0.02) after ozone versus CA (-2.32 ± 0.41% vs. -1.13 ± 0.34%). Similarly, changes in %PMN were greater after ozone (54.0 ± 4.6%) than CA (38.3 ± 3.7%) exposure (P < 0.001). Symptom scores were not different between ozone versus CA. There were no significant differences in changes in FEV(1), FVC, and %PMN between subjects with GSTM1-positive and GSTM1-null genotypes.
Exposure of healthy young adults to 0.06 ppm ozone for 6.6 hours causes a significant decrement of FEV(1) and an increase in neutrophilic inflammation in the airways. GSTM1 genotype alone appears to have no significant role in modifying the effects.
Repeated exposure to high concentrations of ozone results first in augmentation (typically on the second day) and then attenuation of pulmonary response in humans. To determine the effects of repeated prolonged low-concentration ozone exposure, we exposed 17 healthy nonsmoking male subjects to 0.12 ppm ozone for 6.6 h on 5 consecutive days. Subjects were also exposed once to filtered air. Volunteers exercised at a ventilation of approximately 39 L/min for 50 min of each hour during the exposure. Spirometry, plethysmography, and symptom responses were obtained before, during, and after each exposure. Nasal lavage and aerosol bolus dispersion were obtained before and after exposure. Spirometry decreased and symptoms increased on the first day. Responses were less on the second day compared with those on the first day, and they were absent compared with control values on the subsequent 3 days of ozone exposure. Percent change in FEV1 after ozone exposure compared with that after air exposure averaged -12.79, -8.73, -2.54, -0.6, +0.18% for Days 1 to 5 of ozone exposure, respectively. FEV1 responses ranged from a zero to 34% decrease on Days 1 and 2. After each exposure, we determined the ratio of SRaw after inhaling a fixed dose of methacholine to SRaw after inhaling saline aerosol, as an index of airway responsiveness. Airway responsiveness was significantly increased after each ozone exposure. The mean ratios were 2.22, 3.67, 4.55, 3.99, 3.24, and 3.74 for filtered air and ozone Days 1 to 5, respectively. Symptoms of cough and pain on deep inspiration increased significantly on ozone Day 1 only.(ABSTRACT TRUNCATED AT 250 WORDS)
We surveyed pulmonologists to determine which procedures they do in practice, where they learned the procedures, and how much training they recommend to attain and maintain clinical competence in each. We mailed a survey to a random sample of 1,000 members of the American College of Physicians who were identified as practicing pulmonologists; 755 (75%) responded. Respondents performed a variety of pulmonary procedures, an average of 17 of the 29 listed. Pulmonologists who were more recent graduates, who worked longer hours, and who were involved in critical care did a greater variety of procedures. Only 26% of practicing pulmonologists currently do all the procedures required for board certification in pulmonary medicine. For each of 13 specific procedures, the number reported done in the past year was generally unrelated to practice factors. Many respondents who learned procedures in practice did so without formal training or supervision. Respondents' recommendations regarding numbers of procedures required to attain or maintain competence did not vary greatly. Pulmonologists vary considerably in the types of procedures they do. Their opinions about the training needed for competence help to better define requirements for training programs. More attention should be focused on training and certifying practicing pulmonologists in procedures learned after formal fellowship training.
Activation of muscarinic receptors in airway smooth muscle leads to breakdown of membrane polyphosphoinositides. In agreement with others, we show here that muscarinic stimulation elicits inositol-1,4,5-triphosphate formation. In addition, we show that carbachol also elicits total diacylglycerol and 1,2-sn diacylglycerol accumulation in a specific and dose-dependent manner (EC50 values: 2.1 x 10(-8) M for 1,2-sn diacylglycerol). The time-course of inositol-1,4,5-triphosphate accumulation is compatible with that of the clonic phase of muscle contraction. Since this derivative can mobilize intracellular Ca2+ stores, it may play a second-messenger role in the initial phase of contraction. The time-course of diacylglycerol accumulation is compatible with the muscarinic-induced tonic phase of smooth-muscle contraction. Carbachol induces similar dose-dependent reductions in isoproterenol-induced muscle relaxation (EC50 values for relaxation concentration-response curves to isoproterenol: 3 x 10(-6) M and 2.1 x 10(-5) M, with carbachol at 10(-7) M and 10(-4) M, respectively), and increases in adenylate cyclase activity (EC50 values for the concentration-response to isoproterenol: 1.2 x 10(-6) M and 1.5 x 10(-5) M, with carbachol at 10(-7) M and 10(-4) M, respectively). Since it is known that carbachol-induced uncoupling of beta 2-adrenergic receptors is proportional to the breakdown of polyphosphoinositides, and that 1,2-sn diacylglycerol is a potent activator of protein kinase C, 1,2-sn diacylglycerol could be mediating the uncoupling of beta 2-adrenergic receptors, via activation of alpha-protein kinase C and subsequent phosphorylation of receptor, and/or cyclase, and/or G proteins.(ABSTRACT TRUNCATED AT 250 WORDS)
Once-weekly rifapentine 600 mg plus isoniazid (INH) during the continuation phase treatment of tuberculosis is associated with a relapse rate higher than that of twice-weekly rifampin plus INH. The safety and tolerability of higher rifapentine doses need to be determined. We conducted a prospective, randomized, double-blind trial of rifapentine at three doses (600, 900, and 1,200 mg) plus INH 15 mg/kg once weekly in the continuation phase treatment of culture-positive tuberculosis in 150 human immunodeficiency virus-seronegative adults. Outcome measures were discontinuation of therapy for any reason and adverse events on therapy. Treatment was discontinued in 3 of 52 (6%), 2 of 51 (4%), and 3 of 47 (6%) in the rifapentine 600-, 900-, and 1,200-mg treatment arms, respectively. Only one discontinuation, in the rifapentine 1,200-mg arm, was due to an adverse event possibly associated with study therapy. There was a trend toward more adverse events, possibly associated with study therapy, in the highest-dose arms (p = 0.051). Rifapentine 900-mg, once-weekly dosing appears to be safe and well tolerated and is being evaluated in Phase III efficacy trials of treatment of latent tuberculosis. Further evaluation of the safety and tolerability of rifapentine 1,200 mg is warranted.
The pharmacokinetics of rifapentine at 600, 900, and 1,200 mg were studied during once-weekly continuation phase therapy in 35 patients with tuberculosis. Mean area under the plasma concentration-time curve (AUC(0-infinity)) increased significantly with dose (rifapentine AUC(0- infinity): 296, 410, and 477 microg.hour/ml at 600, 900, and 1,200 mg, respectively; p = 0.02 by linear regression). In multivariate stepwise regression analyses, AUC(0-infinity) values for rifapentine and the active 25-desacetyl metabolite were associated with drug dose and plasma albumin concentration, and were lower among men and among white individuals. Fifty-four percent of patients had total (free and protein-bound) plasma concentrations of rifapentine and of desacetyl rifapentine detected for more than 36 hours after clearance of concurrently administered isoniazid. Serious adverse effects of therapy in these study patients were infrequent (1 of 35 cases; 3%) and not linked with higher rifapentine AUC(0-infinity) or peak concentration. The present pharmacokinetic study supports further trials to determine the optimal rifapentine dose for treatment of tuberculosis.
When pulmonary hypertension occurs in the face of hypoxia there is remodeling of all three layers of the pulmonary vessels, but in particular, there is an increase in number of adventitial fibroblasts. Hypoxia causes vasoconstriction in the pulmonary circulation and vasodilation in the systemic circulation. We hypothesized that there are fundamental differences in oxygen sensing and cell signaling between systemic and pulmonary artery cells in response to hypoxia. Here, we determined the effect of hypoxia either alone or in combination with known growth factors such as serum, endothelin-1 (ET-1), and platelet-derived growth factor (PDGF) on the proliferative responses of bovine pulmonary artery and mesenteric artery fibroblasts. Fibroblasts were obtained from primary cultures. Growth was assessed by [3H]thymidine incorporation. Inositol 1,4,5-triphosphate (IP3) generation was measured using a competitive binding assay. Hypoxia alone increased proliferation of pulmonary artery fibroblasts (611 +/- 24%), but not in those from the mesentery. Furthermore, hypoxia had the effect of increasing the replicative response of pulmonary fibroblasts to serum and PDGF, but no change was observed in the mesenteric cells. ET-1 had no effect on growth of either cell type. PDGF gave rise to a significant elevation in IP3 production under hypoxic conditions in the pulmonary artery cells (234%), but not in the mesenteric cells. ET-1 caused no change in IP3 production in any cell type. These data suggest that hypoxia sensitizes pulmonary artery fibroblasts to the proliferative effect of mitogens through a pathway that is not present, or is present but repressed, in the mesenteric cells.
Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n = 96) and at an altitude of 1,400 meters (n = 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa(O(2)), Pa(CO(2)), pH, and calculated alveolar-arterial PO(2) difference (AaPO(2)). CO-oximeter variables were Hb, COHb, MetHb, and Sa(O(2)). Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and cross-product terms; (2) simple equations, including only the variables that explained at least 3% of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa(O(2)) with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa(O(2)) slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters.
Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.
The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.
An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.
Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consistently shown dyspnea stimuli to be correlated with activation of cortico-limbic areas involved with interoception and nociception. Endogenous and exogenous opioids may modulate perception of dyspnea. Instruments for measuring dyspnea are often poorly characterized; a framework is proposed for more consistent identification of measurement domains.
Progress in treatment of dyspnea has not matched progress in elucidating underlying mechanisms. There is a critical need for interdisciplinary translational research to connect dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.
We recently reported strong bactericidal activity of the oxazolidinone PNU-100480 and its ability to increase the initial bactericidal effect of various combinations of first-line tuberculosis drugs and moxifloxacin in a murine model.
To investigate whether the addition of PNU-100480 to the standard first-line regimen of rifampin, isoniazid, and pyrazinamide could shorten the duration of treatment necessary to prevent relapse after treatment discontinuation.
Following aerosol infection with Mycobacterium tuberculosis H37Rv and a 13-day incubation period, control mice were treated with the first-line regimen while test mice received the same regimen with PNU-100480 or linezolid added for the first 2 or 4 months. Efficacy was assessed on the basis of quantitative cultures of lung homogenates performed monthly during treatment and 3 months after completion of 3, 4, 5, or 6 months of treatment to determine the relapse rate.
After 2 months of treatment, mice receiving PNU-100480 in addition to the first-line regimen had lung CFU counts two orders of magnitude lower than control mice receiving the first-line regimen alone. Relapse rates after 4 months of treatment were 90, 35, and 5% when PNU-100480 was added to the first-line regimen for 0, 2, and 4 months, respectively. When the total treatment duration was 3 months, relapse rates were 85 and 35 to 45% when mice received PNU-100480 for 2 and 3 months, respectively; all control mice remained culture positive at the time of treatment completion with 17 to 72 CFU per lung. Addition of linezolid to the first-line regimen had an antagonistic effect resulting in higher CFU counts and failure to render mice culture-negative in 4 months of treatment.
Together with previous findings, these results confirm that PNU-100480, which is now in Phase I clinical testing, has sterilizing activity in the murine model and suggest that it may be capable of shortening treatment duration for drug-susceptible as well as drug-resistant tuberculosis in humans.
Persistent pulmonary hypertension secondary to meconium aspiration syndrome is an important cause of morbidity and mortality in the neonatal population. We investigated the use of the phosphodiesterase-5 inhibitor sildenafil, in its intravenous form, as a pulmonary vasodilator in a model of meconium aspiration syndrome. Pulmonary hypertension was induced in 18 piglets, by endotracheal instillation of human meconium, 6 piglets subsequently received an infusion of intravenous sildenafil for 2 hours, 6 received inhaled nitric oxide for 2 hours, and 6 control animals received no additional intervention. Meconium aspiration increased pulmonary vascular resistance by 70%, and increased oxygenation index by over 100%. Pulmonary vascular resistance remained elevated for the remainder of the study period in control animals. Inhaled nitric oxide reduced the pulmonary vascular resistance by 40% after 2 hours of treatment; intravenous sildenafil completely reversed the increase in pulmonary vascular resistance within 1 hour of commencing the infusion. Neither agent had an effect on systemic hemodynamics. Sildenafil also increased cardiac output by 30%, but while doing so did not adversely influence oxygenation. Intravenous sildenafil is a selective and highly effective pulmonary vasodilator, which is at least as effective as inhaled nitric oxide, in this model of neonatal persistent pulmonary hypertension.
Ventilation was measured in 31 difficult-to-wean patients while pressure support (PS) was reduced by 5 cm H2O every 20 min. Weaning had to be aborted in 14 of 31 patients (Group F) because they met predefined distress criteria. The remaining 17 patients who were able to complete the "weaning test" (Group S) had larger static respiratory compliances (Cstat = 0.08 +/- 0.02 versus 0.05 +/- 0.01 L/cm H2O, p < or = 0.05) and a lower dead space to tidal volume ratio (0.55 +/- 0.05 versus 0.64 +/- 0.06, p < or = 0.05). Group S patients had a larger tidal volume (VT) than did those of Group F at most PS settings. The groups differed with respect to VT maintenance during PS withdrawal (p < 0.01). In Group S, VT fell exponentially with machine support and stabilized at PS levels between 5 and 10 cm H2O. In contrast, Group F patients defended VT at higher PS settings but were unable to maintain VT during distress. Ventilatory response parameters such as the rapid shallow breathing index were of limited value in predicting weaning outcome and yielded receiver operator curve area values between 0.66 and 0.82 over the range of PS settings tested. We conclude that the gradual withdrawal of machine support does not facilitate the recognition of impending respiratory failure.
According to international guidelines, the level and adjustment of antiinflammatory treatment for asthma are based solely on symptoms and lung function. We investigated whether a treatment strategy aimed at reducing airway hyperresponsiveness (AHR strategy) in addition to the recommendations in the existing guidelines (reference strategy) led to: (1) more effective control of asthma; and (2) greater improvement of chronic airways inflammation. To accomplish this, we conducted a randomized, prospective, parallel trial involving 75 adults with mild to moderate asthma who visited a clinic every 3 mo for 2 yr. At each visit, FEV1 and AHR to methacholine were assessed, and subjects kept diaries of symptoms, beta2-agonist use, and peak expiratory flow (PEF). Medication with corticosteroids (four levels) was adjusted according to a stepwise approach (reference strategy), to which four severity classes of AHR were added (AHR strategy). At entry and after 2 yr, bronchial biopsies were obtained by fiberoptic bronchoscopy. Patients treated according to the AHR strategy had a 1.8-fold lower rate of mild exacerbations than did patients in the reference strategy group (0. 23 and 0.43 exacerbation/yr/patient, respectively). FEV1 also improved to a significantly greater extent in the AHR strategy group (p </= 0.05). In bronchial biopsies this was accompanied by a greater reduction in thickness of the subepithelial reticular layer in the AHR strategy group than in the reference strategy group (mean difference [95% confidence interval (CI): 1.7 micrometers (0.2 to 3.1) micrometers]). The changes in AHR in both strategy groups were correlated with eosinophil counts in the biopsies (r = -0.48, p = 0.003). We conclude that reducing AHR in conjunction with optimizing symptoms and lung function leads to more effective control of asthma while alleviating chronic airways inflammation. This implies a role for the monitoring of AHR or other surrogate markers of inflammation in the long-term management of asthma.
The role of lipoxygenase metabolites in the pathogenesis of endotoxin (LPS)-induced lung injury remains to be clarified. We investigated the contribution of peptide leukotrienes to LPS-induced acute lung injury using a potent antagonist, ONO-1078 (ONO). Experimental groups consisted of a saline group (n = 10), an LPS group (n = 9) injected intravenously with 2 mg E. coli LPS, an ONO group (n = 8) receiving 30 mg/kg of intraperitoneal ONO, and an LPS+ONO group (n = 6) receiving 30 mg/kg of ONO intraperitoneally 10 min before the LPS injection. The [125I]albumin lung plasma ratio, which is a parameter of acute lung injury, was significantly increased (p < 0.01) in the LPS group compared with the saline, ONO, and LPS+ONO groups. The [125I]albumin BAL fluid plasma ratio was also increased (p < 0.01) in the LPS group compared with the other groups. ONO pretreatment attenuated the LPS-induced increases in neutrophil counts in the BAL fluid. In vitro studies showed that ONO suppresses the neutrophil chemotaxis induced by LTB4, zymosan-activated serum, and FMLP. We conclude that (1) ONO-1078 attenuates LPS-induced acute lung injury; and (2) this effect appears mainly a result of its potent antagonistic actions against peptide leukotrienes and also, in part, the suppression of neutrophil chemotaxis.
We evaluated the effect of ONO-1078, a selective leukotriene-C4, -D4, and -E4-receptor antagonist, on bronchoconstriction intensity during inhalation challenge with dipyrone (a pyrazolone derivative) in six aspirin-sensitive asthmatics. A double-blind, randomized, crossover design was used. After ingestion of 225 mg ONO-1078 or matching placebo, subjects underwent bronchial provocation with dipyrone on two occasions, separated by 4 wk. Aerosol inhalation of dipyrone was performed increasing the concentration stepwise from 0.08 to 10% (wt/vol). FEV1 was measured every 10 min up to 30 min after inhalation of each concentration. Threshold concentrations causing a fall in FEV1 > or = 20% of baseline value were 0.4% in four subjects and 2% in the other two on the placebo day. After pretreatment with ONO-1078, threshold concentration was 10% in two subjects, and no fall in FEV1 was observed in the other four, even after inhalation of 10% dipyrone. Values of PD20 were 21.9 +/- 8.2 units (mean +/- SEM) after placebo and 311.6 +/- 40.3 units after ONO-1078, respectively, and a statistically significant difference occurred (p < 0.001). Provocation of bronchoconstriction was completely inhibited in subjects whose plasma ONO-1078 levels were more than 0.5 microgram/ml. These results support the hypothesis that sulfidopeptide leukotriene-induced bronchoconstriction is one important component in the pathophysiology of aspirin-induced asthma.
Polymorphisms in the tumor necrosis factor and interleukin-10 genes, linked to cytokine inducibility, may influence the inflammatory response to infection. We studied the biallelic interleukin-10-1082 promoter, the tumor necrosis factor-alpha-308 promoter, and the lymphotoxin-alpha polymorphisms with regard to the development of septic shock in pneumococcal infection. Sixty-nine patients with pneumococcal disease (61 patients with community-acquired pneumonia, 5 patients with meningitis, and 3 patients with pneumonia and meningitis) and 50 age-matched control subjects were included. The polymorphisms were determined by the polymerase chain reaction. In patients with pneumococcal disease, the lipopolysaccharide-stimulated tumor necrosis factor and interleukin-10 release from whole blood were measured by ELISA. Sepsis severity was documented according to standard criteria. No significant genotypic differences were seen between patients and control subjects. Thirteen of 69 patients with pneumococcal disease developed septic shock. Interleukin-10 allele G homozygous patients had the highest risk for septic shock (odds ratio of 6.1; 95% confidence interval, 1.4-27.2; corrected p = 0.024). The stimulated interleukin-10 release was highest in interleukin-10 G homozygous patients (p = 0.04). In conclusion, interleukin-10 polymorphism, associated with high interleukin-10 inducibility, might influence the outcome of pneumococcal infection via induced immunosuppression and impaired bacterial clearance.
Complement in the human respiratory tract protects the host from invading microorganisms and from other inhaled insults. However, complement may also lyse the host's respiratory tract cells, leading to tissue injury. In many extrapulmonic tissues, cells express cell-membrane complement regulatory glycoproteins that protect the cells from complement-induced lysis. To determine whether these glycoproteins are expressed in human respiratory tract tissue, we studied tissue biopsies of healthy and diseased human respiratory tract from nose to alveoli for the presence of four cell-membrane complement regulatory glycoproteins (membrane cofactor protein [MCP], decay-accelerating factor [DAF], CD59, and complement receptor type 1 [CR1]) using an immunoperoxidase technique. In addition, to establish a model for in vitro studies of these glycoproteins in respiratory cells, we studied whether they are expressed in cultured nasal epithelial cells, using the same technique. Altogether, 26 tissue specimens from 22 patients were studied. We found that normal human respiratory tract from nose to alveoli express MCP, DAF, and CD59, but not CR1, and that this expression increases in inflammation and in lung cancer. In addition, expression in nasal epithelial cells is retained under cell culture conditions. These findings suggest that human respiratory tract tissue may regulate complement activation on its surface in order to avoid self-injury. We propose that imbalances in the mechanism that regulates cell-membrane complement may predispose the respiratory tract to tissue injury and disease, and that iatrogenic modulation of such imbalances may help to prevent these adverse consequences.
A 40-yr-old Hispanic man presented to NJCIRM with end-stage lung disease. Evaluation of this patient 10 yr earlier noted bronchiectasis, normal sweat electrolytes, pancreatic sufficiency, delayed progression of pulmonary disease, and a sperm biopsy consistent with fertility. At the time of admission bronchiectasis was extensive. DNA testing demonstrated homozygosity for the 3849+10kb C > T cystic fibrosis (CF) allele. This is the first description of homozygous expression of this allele in a male patient. Confirmation of fertility was established by demonstrating that his children were carriers of this allele. This patient emphasizes the importance of DNA testing for atypical CF alleles in patients with bronchiectasis of undetermined cause even in the presence of fertility, normal pancreatic function, and normal sweat electrolytes.
The integrin alpha1beta1 (very late antigen-1; CD49a/CD29) is a major adhesion receptor for collagen I, IV, and VI, and its induced expression on activated monocytes and lymphocytes plays a central role in their retention and activation at inflammatory sites in autoimmune pathologies. However, the role of alpha1beta1 in allergic settings has not been explored. In this study, we show that a single 45-mg dose of aerosolized monoclonal antibody AQC2 to the alpha1 chain of human and sheep very late antigen-1, given 30 minutes before challenge, blocks both the allergen-induced late response and the associated airway hyperresponsiveness, functional indicators of allergen-induced inflammation, in sheep. AQC2 does not affect the early response. Consistent with these effects, AQC2 tended to reduce the cell response associated with local antigen instillation. An isotype-matched control antibody had no protective effects. Two humanized versions of AQC2, a wild-type IgG1 and an aglycosyl form of the same monoclonal antibody, which has reduced Fc receptor-mediated effector functions, are equally effective in blocking the antigen-induced late response and airway hyperresponsiveness in the sheep model. These data suggest that mononuclear leukocyte adhesion-dependent pathologies contribute to allergic lung disease and provide proof-of-concept that antagonists of alpha1 integrins may be useful in preventing these events.
Noninflammatory structural alterations, variously referred to as airway remodeling, are well documented in the asthmatic airway. However, the pathogenesis of these alterations, the importance of airway remodeling in generating the asthma phenotype, and the natural history of airway remodeling responses have not been adequately defined. Because exaggerated cytokine production is a characteristic feature of the asthmatic airway, we used constitutive and inducible overexpression transgenic systems to investigate the contributions that interleukin 11 (IL-11) and IL-13 might make to airway remodeling responses. These studies demonstrated that both cytokines produce responses in the murine airway with features similar to those in human asthmatic tissues. IL-11 caused airway fibrosis with the enhanced accumulation of interstitial collagens, myocytes, and myofibroblasts. IL-13 caused mucous metaplasia, enhanced mucin gene expression, enhanced tissue hyaluronic acid accumulation, and subepithelial fibrosis. Importantly, IL-11 was detected most readily in tissues from asthmatic subjects with severe airway remodeling that was similar to that seen in the IL-11 transgenic mice. In addition, IL-11 was shown to inhibit asthma-like inflammation while stimulating airway fibrosis. This suggests that IL-11 elaboration is, in part, an attempt at airway healing. Last, a novel triple transgenic system is described that allows transgene expression to be regulated in a true "on/off" manner. This system may be useful in defining the reversibility of transgene-induced airway remodeling responses.
Eleven years after Lung Health Study (LHS) entry, we performed spirometry in 77.4% of surviving participants who enrolled in a long-term follow-up study. Those not enrolling tended to be younger male heavy smokers who continued to smoke during the LHS. Their initial LHS lung function, after adjustment for these factors, did not differ from that of enrollees. Smoking habits by original LHS treatment groups (smoking intervention vs. usual care) tended to converge, but 93% of participants who were abstinent throughout the LHS were still abstinent at 11 years. Differences in lung function between treatment groups persisted; smoking intervention participants had less decline in FEV(1) than usual care participants. Men who quit at the beginning of the LHS had an FEV(1) rate of decline of 30.2 ml/year, whereas women who quit declined at 21.5 ml/year. Men continuing to smoke throughout the 11 years declined by 66.1 ml/year, and women continuing to smoke declined by 54.2 ml/year. When decline in FEV(1) was expressed as a percentage of predicted normal value, no significant sex-based difference was apparent among continuing smokers. At 11 years, 38% of continuing smokers had an FEV(1) less than 60% of the predicted normal value compared with 10% of sustained quitters.
The long-term respiratory sequelae of infants born extremely preterm (EP) and now graduating from neonatal intensive care remains uncertain.
To assess the degree of respiratory morbidity and functional impairment at 11 years in children born EP (i.e., at or less than 25 completed weeks of gestation) in relation to neonatal determinants and current clinical status.
Pre- and postbronchodilator spirometry were undertaken at school in children born EP and classroom control subjects. Physical examination and respiratory health questionnaires were completed. Multivariable regression was used to estimate the predictive power of potential determinants of lung function.
Spirometry was obtained in 182 of 219 children born EP (129 with prior bronchopulmonary dysplasia [BPD]) and 161 of 169 classmates, matched for age, sex, and ethnic group. Children born EP had significantly more chest deformities and respiratory symptoms than classmates, with twice as many (25 vs. 13%; P < 0.01) having a current diagnosis of asthma. Baseline spirometry was significantly reduced (P < 0.001) and bronchodilator responsiveness was increased in those born EP, the changes being most marked in those with prior BPD. EP birth, BPD, current symptoms, and treatment with beta-agonists are each associated independently with lung function z-scores (adjusted for age, sex, and height) at 11 years. Fifty-six percent of children born EP had abnormal baseline spirometry and 27% had a positive bronchodilator response, but less than half of those with impaired lung function were receiving any medication.
After extremely preterm birth, impaired lung function and increased respiratory morbidity persist into middle childhood, especially among those with BPD. Many of these children may not be receiving appropriate treatment.
11beta-hydroxysteroid dehydrogenases (11beta-HSD) are responsible for the conversion of bioactive glucocorticoids to and from inactive metabolites. 11beta-HSD2 is generally considered a high-affinity inactivator of natural glucocorticoids, although its activity with synthetic compounds in vivo is unknown. Inhaled corticosteroids (ICS) remain the primary antiinflammatory agents for treating asthma, but little is known about their metabolism in the lung. The aims of this study were to determine whether the 11beta-HSD2 enzyme can be localized to human airway tissue and whether differential expression of this enzyme relates to asthma severity and ICS needs. We studied airway biopsy specimens from 22 asthmatic subjects, in two groups: (1) a group not treated with ICS (n = 7); and (2) a group treated with ICS (range: 200 to 1,500 microg/d; n = 15). A control population consisted of nine nonasthmatic subjects. Immunostaining was done with an immunopurified antibody to human 11beta-HSD2. Immunoreactivity was generally localized to the endothelium of vessels in the lamina propria and to airway epithelium both in asthmatic patients and nonasthmatic controls. There was a statistically significant inverse relationship between the ICS dose required for effective treatment and the extent of epithelial 11beta-HSD2 staining (r = -0.44; p = 0.04). This is consistent with 11beta-HSD2 acting as an oxidoreductase that regenerates rather than inactivates ICS. This study suggests that glucocorticoid sensitivity in the lung is not determined by ICS breakdown, but may be related to 11beta-HSD2 sustaining the activation of synthetic glucocorticoids.
The effect of volume history on forced expiratory flow rates has been reported to differ between patients with asthma and healthy persons, and it has been hypothesized that the peripheral airway inflammation of patients with asthma may underlie this difference. There are no published data, however, on the distribution of such volume history effects or the relation of these effects to airways disease in children. We obtained combined partial and maximal forced expiratory flow-volume curves on 1,834 children, age 10-11 yr, in eight communities in the United States and Canada. The effect of a deep inhalation on forced expiratory flow rates at low lung volumes was quantitated by the ratio of V (30) during a maximal expiratory maneuver (V (30M)) to V (30) during a partial expiratory maneuver (V (30P)). The V (30M)/V (30P) ratio was slightly higher among girls than boys (1.26 versus 1.18, p = 0.0001) indicating that a deep inhalation increased V (30) slightly more among girls than among boys. The V (30M)/V (30P) ratio was related to neither history of asthma nor to maternal smoking. In contrast, most spirometric indices from either the maximal or the partial expiratory flow-volume curve were lower in association with a history of asthma or a report of maternal smoking. The ratio of FEF(25-75)/FVC was particularly consistent as a measurement that discriminated both of these effects in boys and girls. These results suggest that the measurement of volume history effects offers no benefits for epidemiological studies of childhood respiratory disease whereas spirometric indices such as the FEF(25-75)/FVC ratio are quite sensitive to the effects of asthma and environmental tobacco smoke exposure on the airways.
During a period of 11 yr (1983-1993) 137 clinical isolates of Mycobacterium simiae obtained from 75 patients were identified in a University hospital in San Antonio, Texas. One hundred twenty-eight isolates (93%) were from a pulmonary source, four (3%) from blood, and five from other sites including skin, urine, lymph node, bone marrow, and brain. Of 62 evaluable patients, six (10%) had definite infection, nine (14%) had probable disease, and 48 (76%) were thought to be colonized. During the last 2 yr of the study (1992 and 1993), M. simiae became the second most frequently isolated nontuberculous mycobacterium at this institution surpassed only by Mycobacterium avium complex. There are limited data about effective treatment for this multidrug-resistant organism. New macrolides, quinolones, ethambutol, clofazimine, and aminoglycosides are promising therapeutic agents.
Low molecular weight heparins are as effective as unfractionated heparin in deep-vein thrombosis (DVT) prophylaxis for major surgery. However, there is no evidence nor consensus for prophylaxis in medical patients. We compared the efficacy and safety of nadroparin calcium (nadroparin) with placebo in medical patients at high risk of DVT. A total of 223 patients mechanically ventilated for acute, decompensated chronic obstructive pulmonary disease, were randomized to treatment with subcutaneous nadroparin adjusted for body weight (0.4 ml, i.e., 3,800 AXa IU, or 0.6 ml, i.e., 5,700 AXa IU) or placebo. The average duration of treatment was 11 d. The incidence of DVT in patients receiving nadroparin was significantly lower than that in patients receiving placebo (15.5 versus 28.2%; p = 0.045). Although the incidence of adverse events was high in both groups, there were no significant differences between nadroparin and placebo for total adverse events (46.3 versus 39.8%; p = 0.33), serious adverse events (25.0 versus 19.5%; p = 0.32), or those resulting in early permanent discontinuation of treatment (12.0 versus 8.8%; p = 0.44). The most common adverse event was hemorrhage. There was the same number of deaths in both treatment groups. Subcutaneous nadroparin resulted in 45% decrease in incidence of DVT compared with placebo.
All human immunodeficiency virus type 1 (HIV-1) infected adult patients referred to the Division of Pulmonary Diseases of the Centre Hospitalier de Kigali, Rwanda for evaluation of a pulmonary disease of undetermined etiology (PDUE) were investigated by fiberoptic bronchoscopy using both bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB). During a 10-mo period 111 HIV-1 infected patients with PDUE were examined, of whom 47 (42%) fulfilled the World Health Organization (WHO) clinical case definition for acquired immunodeficiency syndrome (AIDS) and seven (6%) had an AIDS-defining illness. Nonspecific interstitial pneumonitis was diagnosed in 42 (38%) patients, tuberculosis in 25 (23%), cryptococcosis in 14 (13%), Kaposi's sarcoma (KS) in 10 (9%), Pneumocystis carinii pneumonia (PCP) in five (5%). The diagnosis remained undetermined in 18 (16%) patients. Chest radiograph patterns were generally nonspecific. TBB and BAL had diagnostic yields of 82 and 26% of all final diagnoses, respectively. Our study on Rwandese HIV-1-infected patients with PDUE provides evidence for a large spectrum of pulmonary diseases with relative frequencies differing strikingly from those in developed countries. Detailed investigations confirm the rarity of PCP in Africa and highlight nonspecific interstitial pneumonitis as the predominant diagnosis of PDUE. Empiric antituberculosis treatment is justified in the absence of clinical manifestations suggestive of a specific diagnosis and while awaiting the results of the diagnostic procedures. Primary prophylaxis for PCP would not be appropriate in Africa.
Although the duration and amount of cigarette smoking correlate with reduction in pulmonary function, there is still variation among individual responses. IL-13 is involved in pulmonary inflammation, remodeling, and susceptibility to chronic obstructive pulmonary disease (COPD).
We investigated whether the relationships between smoking and the lung function measures FEV(1) and FEV(1)/FVC ratio are modulated by IL13 polymorphisms.
Smokers (>or=20 pack-years), aged at least 40 years old (n = 1,073), were genotyped for three single nucleotide polymorphisms (SNPs; -1112C/T [rs1800925], +2044G/A [rs20541, R130Q], and +2525G/A [rs1295685]) in the IL13 gene. Linear, quantile, and logistic regression methods were used to assess the effect of cigarette smoking (pack-years), IL13 polymorphisms, and their interaction on %predicted FEV(1) and FEV(1)/FVC ratio. Age, sex, and current smoking status were included as confounders.
The number of pack-years smoked was associated with a lower value for both %predicted FEV(1) and FEV(1)/FVC (P < 0.001). The three SNPs were not associated with lung function measures; however, there was a significant combined effect between smoking and the promoter polymorphism -1112C/T on %predicted FEV(1) (P for interaction < 0.03 for mean %predicted FEV(1) and < 0.0001 for 90th percentile %predicted FEV(1)). Every 20-pack-year increment in smoking was associated with a 2.4% reduction in mean %predicted FEV(1) in the common homozygous (CC) or heterozygous (CT) promoter genotypes, and an 8.2% reduction in mean %predicted FEV(1) in minor allele homozygotes (TT, recessive model).
An IL13 polymorphism in the promoter region may modulate the adverse effects of cigarette smoking on pulmonary function in long-term cigarette smokers.
The prognostic significance of delirium symptoms in intensive care unit (ICU) patients with focal neurologic injury is unclear.
To determine the relationship between delirium symptoms and subsequent functional outcomes and quality of life (QOL) after intracerebral hemorrhage.
We prospectively enrolled 114 patients. Delirium symptoms were routinely assessed twice daily using the Confusion Assessment Method for the ICU by trained nurses. Functional outcomes were recorded with modified Rankin Scale (scored from 0 [no symptoms] to 6 [dead]), and QOL outcomes with Neuro-QOL at 28 days, 3 months, and 12 months.
Measurements and main results:
Thirty-one (27%) patients had delirium symptoms ("ever delirious"), 67 (59%) were never delirious, and the remainder (14%) had persistent coma. Delirium symptoms were nearly always hypoactive, were detected mean 6 days after intracerebral hemorrhage presentation, and were associated with longer ICU length of stay (mean 3.5 d longer in ever vs. never delirious patients; 95% confidence interval, 1.5-8.3; P = 0.004) after correction for age, admit National Institutes of Health (NIH) Stroke Scale, and any benzodiazepine exposure. Delirium symptoms were associated with increased odds of poor outcome at 28 days (odds ratio, 8.7; 95% confidence interval, 1.4-52.5; P = 0.018) after correction for admission NIH Stroke Scale and age, and with worse QOL in the domains of applied cognition-executive function and fatigue after correcting for the NIH Stroke Scale, age, benzodiazepine exposure, and time of follow-up.
After focal neurologic injury, delirium symptoms were common despite low rates of infection and sedation exposure, and were predictive of subsequent worse functional outcomes and lower QOL.
To investigate genetic factors in asthma and atopy, we sought allelic associations for 12 markers near candidate loci for serum total, immunoglobulin E (IgE), and bronchial hyperresponsiveness (BHR) to inhaled histamine in 131 families comprising 685 individuals, selected randomly without regard to atopy or asthma. Nonparametric linkage and association analyses were performed with the Nonparametric Analysis of Lineage and Association (NOPAR) program, and parametric analyses were performed with the Complex Inheritance with Diathesis and Severity (COMDS) program on an ordered polychotomy of ranked scores. On chromosome 11q, allele 168 at the D11S527 locus was significantly associated with BHR (p<0.0003) but not with log IgE. At the D11S534 locus, allele 235 was significantly associated with log IgE (p = 0.007) but not with BHR. Both D11S527 and D11S534 were too distant from the gene encoding the high-affinity IgE receptor FcepsilonRIbeta to account for the association. At the interleukin-9 (IL-9) locus, the 118 allele showed significant association with serum total IgE (p<0.003) but not with histamine BHR. Parametric tests are more conservative, perhaps because they demand consistency with mendelian inheritance and tight linkage. These findings provide support for the view that both chromosomes 5 and 11 may contain genes relevant to asthma and atopy, a possible candidate being the interleukin-4 (IL-4) gene cluster. Because these associations are extremes in a large number of tests, they require confirmation in other samples.
Asthma is a genetically complex disease, and the investigation of putative linkages to candidate loci in independent populations is an important part of the gene discovery process. This study investigated the linkage of microsatellite markers in the 5q and 11q regions to asthma-associated quantitative traits in 121 Australian Caucasian nuclear families. The families were recruited on the basis of a child proband: a cohort of 95 randomly recruited families of unselected probands (n = 442 subjects) and a cohort of 26 families of probands selected on the basis of severe symptomatic asthma (n = 134 subjects). The quantitative traits assessed included serum levels of total IgE and specific IgE to house dust mite and mixed grass, blood eosinophil counts, and the dose-response slope (DRS) of FEV1 to histamine provocation. Multipoint linkage analysis using Haseman-Elston sib-pair methods provided evidence of significant linkage between the chromosome 5q markers and loge total serum IgE levels, specific serum IgE levels, and loge blood eosinophil counts. The chromosome 11q markers showed evidence of significant linkage to specific serum IgE levels. Neither region demonstrated significant linkage to the loge DRS to histamine. Phenotypes were residualized for age and sex. These data are consistent with the existence of loci regulating asthma-associated quantitative traits in both the 5q31-33 and 11q13 chromosomal regions.
Previous studies have suggested that atopy is linked to the beta chain of the high affinity IgE receptor (Fcepsilon R1-beta) on chromosome 11q13. Fcepsilon R1-beta polymorphisms, I181L, V183L, and E237G, are reported to be associated with asthma and atopy. The aim of this study was to investigate linkage to Fcepsilon R1-beta in a UK population and to assess the frequency of the polymorphisms and their association with asthma and atopy. A sample of 131 families was recruited at random with a sample of 109 families ascertained via an asthmatic proband. Each subject completed a written and video-assisted questionnaire and underwent bronchial challenge and skin prick testing. Serum total and specific IgE levels were measured. Quantitative scores were derived for asthma and atopy using principal component analysis. Four microsatellite markers were genotyped, including Fcepsilon R1-beta. The frequency of the I181L and V183L polymorphisms were determined by sequencing, and the E237G polymorphism was determined using the amplification refractory mutation system. We found no evidence for linkage to Fcepsilon R1-beta and only weak evidence for linkage to the less informative marker E237G. We found no examples of the I181L/V183L polymorphism in our population sample. Our study has failed to strengthen the evidence for a candidate gene on chromosome 11q13.
Sarcoidosis is a complex inflammatory disease with a heterogeneous clinical picture. Among others, an acute and chronic clinical course can be distinguished, for which specific genetic risk factors are known.
To identify additional risk loci for sarcoidosis and its acute and chronic subforms, we analyzed imputed data from a genome-wide association scan for these phenotypes.
After quality control, the genome-wide association scan comprised nearly 1.3 million imputed single-nucleotide polymorphisms based on an Affymetrix 6.0 Gene Chip dataset of 564 German sarcoidosis cases, including 176 acute and 354 chronic cases and 1,575 control subjects.
Measurements and main results:
We identified chromosome 11q13.1 (rs479777) as a novel locus influencing susceptibility to sarcoidosis with genome-wide significance. The marker was significantly associated in three distinct German case-control populations and in an additional German family sample with odds ratios ranging from 0.67 to 0.77. This finding was further replicated in two independent European case-control populations from the Czech Republic (odds ratio, 0.75) and from Sweden (odds ratio, 0.79). In a meta-analysis of the included European case-control samples the marker yielded a P value of 2.68 × 10(-18). The locus was previously reported to be associated with Crohn disease, psoriasis, alopecia areata, and leprosy. For sarcoidosis, fine-mapping and expression analysis suggest KCNK4, PRDX5, PCLB3, and most promising CCDC88B as candidates for the underlying risk gene in the associated region.
This study provides striking evidence for association of chromosome 11q13.1 with sarcoidosis in Europeans, and thus identified a further genetic risk locus shared by sarcoidosis, Crohn disease and psoriasis.
The actions of natural and synthetic glucocorticoids are in part determined by 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2). We examined whether carbenoxolone, a potent inhibitor of 11beta-HSD, would potentiate the inhibitory action of dexamethasone on interleukin-8 release from BEAS-2B cells, and whether prolonged treatment with dexamethasone at therapeutic doses would upregulate 11beta-HSD2 in the cells. We found that carbenoxolone increased the potency of dexamethasone almost 10-fold. Reverse transcription-polymerase chain reaction and Western blot revealed that BEAS-2B cells expressed 11beta-HSD2, but not 11beta-HSD1. An enzyme activity assay of the cell homogenate demonstrated only NAD+-dependent dehydrogenase activity. The Km value for cortisol in intact BEAS-2B cells was estimated to be 42 nM. When the cells were incubated with dexamethasone for up to 72 hours at increasing concentrations (10(-9) to 10(-5) M), there were considerable increases in mRNA and protein levels of 11beta-HSD2. Prolonged treatment with dexamethasone also increased the enzyme activity of 11beta-HSD in the cells in a dose- and time-dependent manner, with complete inhibition by RU38486. These results suggest that bronchial epithelial cells possess an autoregulatory system for glucocorticoids in the control of their own bioactive levels by inducing the expression of 11beta-HSD2, and that 11beta-HSD2 in the bronchial epithelium may play a role in the local regulation of inhaled glucocorticoid actions.
Acute lung injury (ALI) is a disease process that is characterized by diffuse inflammation in the lung parenchyma. Recent studies demonstrated that cyclooxygenase-2 (COX-2) induced at the late phase of inflammation aids in the resolution of inflammation by generating 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2). Transcription factor Nrf2 is activated by electrophiles and exerts antiinflammatory effects by inducing the gene expression of antioxidant and detoxification enzymes.
Because 15d-PGJ2 is an endogenous electrophile, we hypothesized that it protects against ALI by activating Nrf2.
To test this hypothesis, we generated a reversible ALI model by intratracheal injection of carrageenin, an inducer of acute inflammation, whose stimulation has been known to induce COX-2.
We found that ALI induced by carrageenin was markedly exacerbated in Nrf2-knockout mice, compared with wild-type mice. Analysis of bronchoalveolar lavage fluids also revealed that the magnitude and the duration of acute inflammation, indicated by albumin concentration and the number of neutrophils, were significantly enhanced in Nrf2-knockout mice. Treatment of wild-type mice with NS-398, a selective COX-2 inhibitor, significantly exacerbated ALI to the level of Nrf2-knockout mice. In the lungs of NS-398-treated wild-type mice, both the accumulation of 15d-PGJ2 and the induction of Nrf2 target antioxidant genes were significantly attenuated. Exogenous administration of 15d-PGJ2 reversed the exacerbating effects of NS-398 with the induction of antioxidant genes.
These results demonstrated in vivo that 15d-PGJ2 plays a protective role against ALI by exploiting the Nrf2-mediated transcriptional pathway.
Effective compliance (time spent at the effective pressure) with nasal CPAP in obstructive sleep apnea has been reported to be poor. The aim of our study was to evaluate effective compliance in a large European multicenter study. One hundred twenty-one consecutive newly treated patients (initial apnea-hypopnea index [AHI] = 62.0 +/- 29. 5/h, AHI under CPAP = 6.4 +/- 8.1/h, CPAP pressure = 8.7 +/- 2.6 cm H(2)O, BMI = 33.1 +/- 6.8 kg/m(2)) were randomly allocated to a group with (MC(+)) (n = 58) or without (MC(-)) (n = 63) a control unit measuring effective compliance at 1, 2, and 3 mo, which was compared with the built-in time counter data. MC(+) data were 94 +/- 10, 98 +/- 5, and 96 +/- 9% of counter data at 1, 2, and 3 mo, respectively. Using criteria of regular use already reported in the literature (at least 4 h of nCPAP per day of use and nCPAP administered more than 70% of the days) we found 77, 82, and 79% compliant patients at 1, 2, and 3 mo, respectively, 79% of the patients meeting these criteria each month. Although there were no pulmonary functions or polysomnographic differences between the two subgroups, the compliant patients did report a greater improvement in minor symptoms. We found a close correlation between effective use of CPAP and the machine run time. The main result of our study was a higher effective compliance than previously reported, approximately 80% of the patients being regular users versus 46% in a previously published study. This may result from different technical and medical follow-up.
Hereditary surfactant protein-B deficiency is an autosomal recessive disorder that causes fatal respiratory distress syndrome in newborns. Seventy percent of the cases of hereditary surfactant protein-B deficiency are caused by homozygosity for the 121ins2 mutation in the surfactant protein-B gene. Individuals heterozygous for this mutation have partial absence of surfactant protein-B and could be at risk of lung disease when exposed to additional risk factors for impaired surfactant function such as tobacco smoking.
To test whether individuals heterozygous for the 121ins2 mutation have reduced lung function and increased risk for chronic obstructive pulmonary disease (COPD) among smokers.
We genotyped 47,600 individuals from the adult Danish general population and recorded smoking habits, spirometry, and hospital admissions due to COPD. The study and findings are limited to Danes/Europeans.
We identified 85 individuals heterozygous for the 121ins2 mutation. Smoking interacted statistically with the 121ins2 genotype in predicting FEV(1) % predicted (P = 0.006), FVC % predicted (P = 0.02) and FEV(1)/FVC (P = 0.002), indicating that the effect of genotype differ by smoking status. Among smokers, 121ins2 heterozygous individuals had 9% reduced FEV(1)% predicted (P = 0.0008), 6% reduced FVC % predicted (P = 0.01) and 6% reduced FEV(1)/FVC (P = 0.00007), compared with wild-types. Also among smokers, 121ins2 heterozygous individuals had odds ratios of 2.4 (95% CI, 1.2-4.8) for spirometry-defined COPD and 2.2 (1.0-5.1) for hospitalization due to COPD. Among never-smokers, 121ins2 heterozygous individuals did not differ from wild-types in lung function or risk of COPD.
Surfactant protein-B 121ins2 heterozygosity is associated with reduced lung function and increased risk for COPD among smokers.
Eosinophilic chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) represents a hard-to-treat subtype of CRS.
To determine the pattern of expression and biologic role of microRNAs (miRNAs) in CRS, particularly in eosinophilic CRSwNP.
Global miRNA expression in sinonasal mucosa from controls, CRS without nasal polyps (CRSsNP), and patients with eosinophilic CRSwNP was compared using miRNA microarrays. MiR-125b expression was detected by means of quantitative reverse-transcriptase polymerase chain reaction. The cellular localization of miR-125b was determined by in situ hybridization. MiR-125b functional assays were performed on airway epithelial cells and mice. MiR-125b expression regulation was studied by tissue and cell culture.
CRSsNP and eosinophilic CRSwNP exhibited distinct miRNA expression profiles. MiR-125b was specifically up-regulated in eosinophilic CRSwNP. MiR-125b was mainly expressed by sinonasal and bronchial epithelial cells. EIF4E-binding protein 1 (4E-BP1) was identified as a direct target of miR-125b. MiR-125b mimic or inhibitor enhanced or decreased IFN-α/β production elicited by dsRNA in vitro or in vivo, respectively. 4E-BP1 expression was decreased, whereas IFN regulatory factor-7 and IFN-β expression was increased, in eosinophilic CRSwNP. IFN-β mRNA levels positively correlated with IL-5 mRNA levels and eosinophil infiltration in sinonasal mucosa. IFN-β stimulated B cell-activating factor of the tumor necrosis factor family production in airway epithelial cells. miR-125b could be induced by lipopolysaccharide, dsRNA, and IL-10.
The up-regulated expression of miR-125b may enhance type I IFN expression through suppressing 4E-BP1 protein expression in airway epithelial cells, which potentially contributes to mucosal eosinophilia in eosinophilic CRSwNP.
Acute renal failure is a common cause of morbidity and mortality in critically ill patients and frequently results from vasoconstrictive ischemic injury to the kidney. Protein and amino acids can vasodilate renal blood vessels. Thus, we tested the hypothesis that enteral feeding could prevent renal ischemic injury using an experimental model in which renal vasoconstriction is believed to cause ischemic renal injury. This study was performed using male Sprague-Dawley rats, and renal injury was induced by glycerol injection into the hind limbs. The resulting muscle necrosis (rhabdomyolysis) causes acute renal injury. In the first part of the study, 35 animals were randomized to a peptide-based enteral diet or water via a duodenal feeding tube and subsequently injected with glycerol. Seventy-eight percent (14 of 18) of the animals receiving the enteral diet survived 3 d compared with 35% (six of 17) of the water-fed animals (p < 0.05). Blood urea nitrogen (47+/-8 versus 137+/-27 mg/dl) and creatinine (0.8+/-0.1 versus 2.0+/-0.3 mg/dl) were significantly lower in the enteral survivors than in the water survivors. In the second part of the study, renal plasma flow (para-aminohippurate clearance) and glomerular filtration rate (insulin clearance) were measured in similarly treated animals (n = 14) 1 d after injury. Renal plasma flow (4.83+/-0.65 versus 2.37+/-0.62 ml/min) and glomerular filtration rate (2.05+/-0.27 versus 0.89+/-0.22 ml/min) were significantly higher in the enteral group than in the water group. These data indicate that enteral feeding can prolong survival and decrease renal injury after glycerol-induced rhabdomyolysis. The mechanism for the protection is partly related to maintenance of renal blood flow.
The National Institutes of Health- National Heart, Lung, and Blood Institute (NIH-NHLBI) convened the Cell Therapy for Lung Disease working group on November 13-14, 2012, to review and formulate recommendations for future research directions. The workshop brought together investigators studying basic mechanisms and the roles of cell therapy in preclinical models of lung injury and pulmonary vascular disease, with clinical trial experts in cell therapy for cardiovascular diseases and experts from NHLBI's Production Assistance for Cell Therapy (PACT) program. The purpose of the workshop was to discuss the current status of basic investigations in lung cell therapy, to identify some of the scientific gaps in current knowledge regarding the potential roles and mechanisms of cell therapy in the treatment of lung diseases, and to develop recommendations to the NHLBI and the research community on scientific priorities and practical steps that would lead to first-in-human trials of lung cell therapy.
C-X-C motif chemokine 13 (CXCL13) mediates B-cell trafficking and is increased, proportionately to disease activity, in many antibody-mediated syndromes. Dysregulated B cells have recently been implicated in idiopathic pulmonary fibrosis (IPF) pathogenesis.
To determine if CXCL13 is associated with IPF progression.
CXCL13 was measured in lungs by DNA microarray and immunohistochemistry, and in plasma by ELISA.
Measurements and main results:
CXCL13 mRNA was threefold and eightfold greater in IPF lungs (n = 92) compared with chronic obstructive pulmonary disease (COPD) (n = 191) and normal (n = 108) specimens, respectively (P < 0.0001). IPF lungs also showed increased CXCL13 staining. Plasma CXCL13 concentrations (pg/ml) were greater in 95 patients with IPF (94 ± 8) than in 128 subjects with COPD (53 ± 9) and 57 normal subjects (35 ± 3) (P < 0.0001). Circulating CXCL13 levels were highest in patients with IPF with pulmonary artery hypertension (P = 0.01) or acute exacerbations (P = 0.002). Six-month survival of patients with IPF in the highest quartile of plasma CXCL13 was 65 ± 10% versus 93 ± 10% in the others (hazard ratio, 5.5; 95% confidence interval, 1.8-16.9; P = 0.0008). CXCL13 increases by more than 50% in IPF serial assays, irrespective of initial values, also presaged respiratory failure (hazard ratio, 7.2; 95% confidence interval, 1.3-40.0; P = 0.008). In contrast, CXCL13 clinical associations in subjects with COPD were limited to modest correlations with FEV1 (P = 0.05) and progression of radiographic emphysema (P = 0.05).
CXCL13 is increased and is a prognostic biomarker in patients with IPF, and more so than in patients with COPD. This contrast indicates CXCL13 overexpressions are intrinsic to IPF, rather than an epiphenomenon of lung injury. The present data implicate CXCL13 and B cells in IPF pathogenesis, and support considerations for trials of specific B-cell-targeted therapies in patients with this intractable disease.
Interleukin (IL)-13 induces important features of bronchial asthma such as eosinophilic infiltration, airway hyperresponsiveness (AHR), and mucus hypersecretion. Although glucocorticoids suppress airway inflammation and remain the most effective therapy for asthma, the effects of glucocorticoids on the IL-13-dependent features are unknown. We studied the effects of dexamethasone on eotaxin production, eosinophil accumulation, goblet cell hyperplasia, and AHR after IL-13 administration into the airways of mice in vivo. MUC5AC gene expression, a marker of goblet cell hyperplasia, was also analyzed. IL-13 alone dose dependently induced AHR. Treatment with dexamethasone inhibited eotaxin expression and completely abolished eosinophil accumulation, but it did not affect AHR, MUC5AC overexpression, or goblet cell hyperplasia induced by IL-13. The effects of tumor necrosis factor-alpha on IL-13-induced AHR were also examined. Tumor necrosis factor-alpha did not affect AHR despite marked enhancement of eosinophil infiltration in IL-13-treated mice. These findings suggest that glucocorticoid is not sufficient to suppress IL-13-induced AHR or goblet cell hyperplasia and that eotaxin expression and eosinophilic inflammation do not have a causal relationship to the induction of AHR or goblet cell hyperplasia by IL-13. Control of steroid-resistant features induced by IL-13, including AHR and mucus production, may provide new therapeutic modalities for asthma.
Interleukin (IL)-13 plays a pivotal role in the pathogenesis of allergic asthma. Passive administration of its monoclonal antibody or soluble receptor to block overproduced IL-13 has been proven to be effective in controlling airway allergic responses in animal models, but these approaches have disadvantages of short half-lives, high costs, and possible adverse effects.
We sought to develop a novel therapeutic strategy through constructing an IL-13 peptide-based vaccine for blocking IL-13 on a persistent effect basis and to evaluate its in vivo effects using a murine model.
To break self-tolerance, truncated hepatitis B core antigen was used as a carrier. Vaccine was prepared by inserting a peptide derived from the receptor binding site of mouse IL-13 into the immunodominant epitope region of the carrier using gene recombination methods. Mice received vaccine subcutaneously three times, and then subjected to intraperitoneal sensitization and intranasal challenge with ovalbumin. Control animals received carrier or saline in place of vaccine.
The vaccine presented as virus-like particles and induced sustained and high titered IL-13-specific IgG without the use of conventional adjuvant. Vaccination significantly suppressed ovalbumin-induced inflammatory cell number, and IL-13 and IL-5 levels in bronchoalveolar lavage fluids. Serum total and ovalbumin-specific IgE were also significantly inhibited. Moreover, allergen-induced goblet cell hyperplasia, lung tissue inflammatory cell infiltration, and pulmonary hyperresponsiveness to inhaled methacholine were significantly suppressed in vaccinated mice.
Our data indicate that IL-13 peptide-based vaccines could be an effective therapeutic approach in the treatment of asthma.
Chronic rhinosinusitis (CRS) without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP) are associated with Th1 and Th2 cytokine polarization, respectively; however, the pathophysiology of CRS remains unclear. The importance of innate lymphoid cells in Th2-mediated inflammatory disease has not been clearly defined.
The objective of this study was to investigate the role of the epithelial cell-derived cytokine IL-33 and IL-33-responsive innate lymphoid cells in the pathophysiology of CRS.
Relative gene expression was evaluated using quantitative real-time polymerase chain reaction. Innate lymphoid cells in inflamed ethmoid sinus mucosa from patients with CRSsNP and CRSwNP were characterized using flow cytometry. Cytokine production from lymphoid cells isolated from inflamed mucosa of patients with CRS was examined using ELISA and intracellular cytokine staining.
Measurements and main results:
Elevated expression of ST2, the ligand-binding chain of the IL-33 receptor, was observed in inflamed sinonasal mucosa from CRSwNP compared with CRSsNP and healthy control subjects. An increased percentage of innate lymphoid cells was observed in inflamed sinonasal mucosa from CRSwNP compared with CRSsNP. ST2(+) innate lymphoid cells are a consistent source of IL-13 in response to IL-33 stimulation. Significant induction of IL-33 was observed in epithelial cells derived from patients with CRSwNP compared with patients with CRSsNP in response to stimulation with Aspergillus fumigatus extract.
These data suggest a role for sinonasal epithelial cell-derived IL-33 and an IL-33-responsive innate lymphoid cell population in the pathophysiology of CRSwNP demonstrating the functional importance of innate lymphoid cells in Th2-mediated inflammatory disease.